Boiler



W. H. RiTTS.

BGILER. Awucm mu man as. 28, ms.

Fatented Marc. 5, 1918.

1 ,258,2%%. 2 SHEETS-SHEET INVENTOR WITNESS -mmmM-Mhm Ha; RIITS.

BOILER. momma mz'o FEB. 28. ms.

1 5 249 med Mali? Q.-

* UNITED STATES PATENT curios.

WILLIAM H. RI'ITS, F ETNA, PENNSYLVANIA, ASSIG-NOR TO PITTSBURGH;PENNSYLVANIA.

' BOILER.

To all whom it may concern:

Be it known that I, WILLIAM H. Rrr'rs, residing at Etna, in the countyof Allegheny and State of Pennsylvania, citizen of the "United States,have invented or discovered certain new and useful Improvements' inBoilers, of which improvements excessive local heating and insure auniform heating of. the tube surfaces. A maxi mum combustion per foot ofgratearea 1s best obtained b the employment of underfeed stokers an aforced draft, the air being directed through the coal into the bed offire; The results that may be expected from the employment of stokingmechanism and forced draft has notbeen obtained for the reason thatprovision was not madeforthe complete combustion ofthe increasedquanties of gases, etc., generated before the same come in contact withthe tubes and boiler proper. As for example, the combustion chamber wasnot made of sutficient size to aflord the space for such expansion as isnecessary for complete combustion of gases,

the exits from the combustion chamber being restricted and solocatedthat the gases are brought into contact with the cold surfaces ofthe water tubes before complete combustion has occurred and are therebyso cooled that further combustion is impossi-.

ble. It has been attempted to relieve the congestion in the combustionchamber by employing ahighstack to increase the rate of flow of thegases from the chamber,.but it was found that thegases flowed toorapidly through the fire-box to permit complete combustion. p I

As for example, it has heretofore been the custom to employ a combustionchamber having a height not substantially greater than one-third and insome cases one-half of the height of the chamber in which the boilerproper is located. In such cases the front wall rising above the top ofthe fire-box, is but a comparatively short distance away from the firstset of tubes and with the usual arrangement of bafiiing, having tilesSpecification of Letters Patent.

uniformly heated from local heating avoided. It is a further object. v

Patented Mar. 5. 1918.

Application filed February 28, 1916. Serial No. 80,912.

GEORGE T. LADD, 0F

located alongthe rear line of tubes from the first set or bank adjacentto the firebox.'

The passage of the products of'co'mbustion from the fire-box to theupper end of the tubes is narrow and being nearly filledwith tubes ofthe first bank, the flow of gases from the fire-box is restricted. Whenemploying a forced draft, gasesare generated more rapidly than undernormal draft conditions, and in order to relieve thecongestion of thefire-box, the pull of the stack is increased, thereby causing theproducts of combustion to move so rapidly that sufficient transmissionof heat to the tubes is impract1cable,=unless the number of passages areincreased with consequent greater draft losses. 4

In the construction above described,

the gases are brought into contact with relatively cold tubes beforecomplete combustion can occur.

Itis the object of the invention described herein to provide a fire-boxor combustion chamber of sufficient size and of such transverse shape asWill permit of the natural upward movement of the gases from the grateand their expansion, thus promoting combustion of all gases and finelydivided solid material carried up by the gases, said combustionchamberbeing so disposed relative to the first bank of tubes that theywillbe' end to end and all" of the inventionto provide for the feedingof fuel into the furnace at a point remote from the heating surfaces ofthe boiler in order that thegas'es'formed in the combustion of the fuelmay be consumed before coming into contact with the surfaces that willcool or tend to cool the gases below i The invention ishereintemperatures at which combustion of the gases can occur.

after more fully described and claimed.

In the accompanyingdrawings forming a part of this specification, thefigure is a sectional elevation of a vertical water-tube boilerincomblnation'with my improved firebox and'combustion chamber, the planeof combustion of gases generated and small particles of solid fuelcarried by the gases and an even uniform a plication of the heatgenerated by such com ustion to the heating surfaces. The firstcondition can be fulfilled by affording opportunity for the gases toexpand and freely intermingle, and avoidmg any material cooling orchilling of any considerable portion of the gases below a temperature atwhich complete combustion will occur and the regeneration of suchpercentages as may be cooled.

i The second condition can be fulfilled by causing portions of the gasesto flow uniformly along the tubes from end to end while combustion isbeing completed and to insure the flow of gases subsequent to suchcomplete combustion, along the entire length of tubes during such passamong the tubes. Care should be taken that the flow of gases should notbe restricted or diverted in any ;such manner as will tend to cause anexcessive heating of the tubes at any point.

Inthe practice of the invention, the boiler proper consisting of upperand lower drums 1 and 2 and vertical connecting tubes, which arereferably separated into a plurality of sets:of banks, as 3, 4, and 5,is arranged in a settin of the usualcombinationhaving back an side walls6 and 7 closely adjacent to the boiler'proper.-.' The combined fire boxand combustion chamber is made of a height approximately equal to thedistance between the upper and lowerdrums and of substantially uniformdepth for its entire height and of a width substantially equal to thewidth of the boiler. The rear wall of the combined fire-box andcombustion cham- Y bar is formed by the first bank of tubes and thebafile 8 arranged therein, and the upper and lower (portions of therespective drums. Fuel is fe by a suitable form of staking mechanismindicated at 12, forthe entire width of the fire-box, air, preferablyunder pressure, being admitted under the grate, 10

- through a pipell. As hereinbefore stated,

provision shouldbe made for so feeding the uel into the furnace thatgases formed by the combustion of the fuel will not be cooled beforecomplete combustion-can occur. In

the construction shown, the stoking mechafire box has been soconstructed and ar- 116 ranged as to cause a restriction of the flow ofhot gases from. the 'fire-box"and allocal ni'sm is arranged to feed thefuel through the front wall of ,the fire box or wall most distant fromthe first bank oftubes and hence the gases generated by the combustionof the fuel on the gratesurfaces will flow directly upward and will notcontact with any of the relatively cool heating surfaces untilopportunity has been afi'orded for a complete combustion of such gases.

gases which comeinto contact with the In such a combined fire-box andcombns tion chamber, the gases will rise up vertically from the pointswhere formed. The tubes of the first bank of tubes will be cooled agreater or less degree and this cooling will tend to cause a downwardfiow along the ing downward will be deflected outward into the gasesmoving up from the fuel bed, and

be regenerated by such hot gases. The gases thus deflected will somodify the action ofthe hot gases on the lower portions of the tubes asto prevent excessive heating.

In operating the boiler, provided the same is properly bafiled, the pullof the stack willv tubes of the first bank. The gases thus flowthoroughmixing of the gases by the circulation due to contact and cooling of thegases with the first bank of tubes as hereinbefore stated.

The provision herein before described for insuring complete combustionand avoiding 4 local heating of the tubes of the'first bank of tubes,would be supplemented by insur- 9 ing a uniform travel of the (gases inthe subsequent passes. To this en the'throat between the upper end ofthe baifieS and the upper drum should extend the entire width ,tomaterially restrict the flow of gases'theres through and the throatsconnecting other passes are preferably simllarly roportloned,

but may be made of slightly ess depth as the rate of travel of the gasescan be maintained by the pull of the stack, the volume of the gasesbeing reduced by. cooling and hence some lessening of the depthsofsuccessive throats would not cause any congestion in the precedingpasses.

After passing through the throat above v the baffle 8, the products ofcombustion flow 7 7 down through the chamber or space in which f I thesecond set of tubes 4 is arranged interioa 'mediate thebaflle 8 and'thebafile 9 are ranged in the rear of the'secondset or bank' of tubes 4.,In leavingthis space or cham-' I her, the gases pass across thelower-portions. of the sets of tubes 4 and 5 and through the space orchamber intermediate thebaflle 9 and the rear wall of theboiler'setting, and

occupied by the third set of tubes 5.-

;In boilers as heretofore constructed, the

excessive heating of the .tubes as hereinbe fore stated such in3uriousheating isdue not only to contact of hot gasesfbnfalso the heat radiatedfrom the walls ofthe' fire box and concentrated .by 'reason oftheirshape and the relation of theirsurfacesto thetubes at the-point ofrestriction of the H products of combustion flowing from" the 'firc-box.r

In the improved construction shown hereof-the boiler and be of such adepth as not such walls will be as evenly distributed set of banks, astoking along the entire length of the tubes as the ing fuel into thefire-box at a heat derived from the gases flowi' g up from thecombustion chamber. I claim herein as my invention:

1. The combination with a boiler consisting ofan upper and a lower drum,and a plurality of sets or banks of tubes connecting said drums, bafllesso arranged substantially parallel with the sets at tubes as to'lurality of vertical and point remote orm transverse dlmensions for theentire height and having a height approximately equal to the distancebetween said drums. I

The combination with a boiler consii ingot an upper and a lower drum,and a plurality of sets or banks of tubes connecting said drums, bafiiwall formed by one of the width of the baflles and inclosing tubes ofthe k, means for introducing fuel into the fire box at a point remotefrom the first set or bank of tubes, and means for introducing air topromote combustion, said combined fi vide connecting throats betweenpasses formed by the bafil chamber formed in part by the fire box andhaving its rear wall formed by oneof the baflles and inclosing tubes,forming the first he entire height and having such a set of banks, astoking mechanism for feedhe1ghtas will permit a practically completeing fuel into the fire-box V combustion of the gases, etc., before thefrom the first set or bank of tubes, gases ass from the combustionchamber. means for introducing air to promote com- 2. 'Ihe combinationwith bustion, said combined fire box and combustion chamber being ofsubstantially uniform the adjacer" e; a COITlbllSblOh ing said drums, baes so arranged substantially parallel with the sets of tubes as to thedistance between said drums.

form a plurality of vertical and connected. In testimony whereof, I havehereunto set passes for the hot gases; a combustion chammy hand. herformed in part by the fire box and hav- WILLIAM H. RITTS. ing its rearwall formed by one of the Witness:

bafiies and inclosing tubes forming the first ALICE A. TRILL. a

mechanism for feed-- and having a height approximately equal to

